Trailer 5 way wiring

[Trailer Dunce]

I have a 4-way connection and bought a new boat that requires a 5-way. The existing 4 wires I can just splice, I don't know how to hook up the 5th wire that controls the brakes. Can anybody help? Thanks.

[ccarlson]

You need to remove your taillight of your tow vehicle, pigtail into the positive of the reverse light and run that back to your trailer connection. You will need someone to hold their foot firmly on the brake as they put the tranny in Reverse so you can see which light goes on when it is in reverse.

As another tip, you can just run a single pole wire connector (or a double pole connector if that's all you can find and only use one run of wire). Simply tape the extra wire to your 4 pole and connect it into your boats 5 pole connection. This way when you tow other trailers with 4 pole flats, you don't have the 5 pole flat connector on your vehicle to deal with. You can still connect a 4 to a 5 but sometimes you have to cut the rubber housing of the 4 pole trailer fitting to fit over the 5 pole flat. Hopefully you're not too confused now!

I should add that the 5th wire that "controls the brakes" as you put it, is normally for deactivating surge brakes when you are trying to backup which is why you connect to the reverse lights. If you have electric brakes, not surge brakes, that is usually not 5 wires and requires a different set up.

ccarlson

[This message has been edited by ccarlson (edited 05-24-2004).]